Erasing attachment for type-writers.



E H. THOMPSON.

ERASINGATTACHMENT FOR TYPE WRiTEHS.

APPLICATION FILED MAN.20. 19w.

- Patented July 10, 1917.

m A g EBASING Arracmvinn'rron TYPE-WRITERS.

ra aaaac.

Specification of Letters Patent.

Patented July 10, 1917..

' Application filed March 20, 1917. Serial no. 156,157. 4

To all whom may concern:

Be it known that I,

ing at Baltimore, in the State of Maryland, have invented certain new and'usefullmprovements in: Erasing Attachments for Typ following'to be 'a full, clear, and exact description of the invention, such as will onable others skilled in the art to which it appertains tomake and" use the same. i This invention relates to erasing attachments for typewriters and has for its object to provide "a device of'this nature which will be efficient. in action and 'more convenient in use than those heretofore proposed.

\Vith these and other objects in view the invention consists in the novel combinations of parts more. fully hereinafter "disclosed and particularly pointed out in the claims.

Referring to the accompanying draw ings forming a part of this specification in which like numerals designate like parts in all the views Figure 1 is a side elevational view of an erasing attachment made in accordance with this invention Fig. 2 is a .plan view of the parts shown in Fig. 1; and

Fig.3 is a side elevation of a modified form of the 'invention.

1 indicates the frame, 2 the platen, 3. the

ratchet operating said platen, and 4 the ribbon of any ordinary style of typewriter. Pivoted to the typewriter frame as at 5 1s the. eraser frame comprising the side bars 6 and 7 the front rod or bar 8, and the depending members 9 as shown. Pivoted to said depending members 9 as at 10 are the short levers 11, carrying at their freeends the rod 12, on which is mounted the gripping member 13- of rubber, or other yield- -ing material. Leading from near each end of the rod 12 and secured thereto at one end are the flexible cords or wires 14 and 15, secured at their other end to; the bell cranks 16 and 17 respectively. The frame members 6 and 7 are provided with the brackets 18 and .19 respectively in which-- said bell cranks are pivoted as at-20. The

bell crank 16 is pivotally connected as at 21 to the core 22 of the so%enoid 23, while the bell crank 17 ispivota ly. connected as at i p whereupon thesprmg wh1ch 1s connected 110 24 to the core 2. of. saidsole de; 7

Eos'rrs H. THOMP- SON, a citizen of the United States, resid-f riters;-'an d I do hereby declare the,

Pivotally mounted to the pivot rod or shaft 5 is the hand operated lever 30 provided with the extensions 31 and 32 cocp erating with the T-shaped bracket 33 having the extensions 34 and 35. The extens1on 32 1s preferably in the form of a knife switch adapted, to make circuit with the contact 36 carried by the arm 6 which is contacts 41 and 42, and at its other end the forked member 48 adapted to straddle the pivot 24 and to be reciprocat'ed by the solenoid core 25 as will be pres ntly explained.

The lower end 48 of the lever 30 is provided with the pin 49 positioned-in the slot 50 with whichone end of the reciprocating member 51 is provided, and the other end of said member 51 is pivoted as at 52 to the detent lever 53 pivoted as at 54 to the frame of the machine, and provided with the detent 55 adapted to engage and disengage the ratchet 3 as will be clear from Fig. 1 of the drawings.

The forward rod or member 8 carried by the side frames 6 and 7 is provided with the depending member 55 carrying an eraser 56 preferably in the form of a rubber disk 'and which can be moved toward and from the platen 2 by turning the said rod 8 in its'bearings and can also be ,slid along said rod 8, all as will be clear from the drawings.

The operation of this improvederaser attachment will be clear from the foregoing but may be briefly summarized as fol lows Si lpposin'g 58 to represent the paper in its position around the platen 2 and supposing it is desired to erase a character or symbol which has just; been impressed thereon, and which therefore lies beneath the ribbon 4. The lever 30 is thrown from its dotted line position shown in Fig. 1 to its full line position shown in said figure,

to said lever as at-61, 'will pass from the left hand side of'the pivot 5, as seen in said Fig. 1, to theright hand side thereof and thus cause the side frames 6 and? to move flOlIltllBll dotted line position shown in Fig."1 to their full lineposition, and said spring 60 will hold the parts in said full line position. v

The gripping member 13 will contact with the platen as is illustrated in its dotted line position, and the circuit having been madebetween the contacts 32 and 36- current will flow' from the battery 38 through :the wire 39, solenoid 23, wire 43 contacts 42 and 41, wire 40, extension 32, contacts and over wire 37 back to said battery 38. The solenoid 23 having been thus energized 'the'two cores 22 and 25 willbesucked into said solenoid whereupon the two bell cranks 16 and 17 will be turned on their pivots 20 and the two flexible cords or connections 14 and 15 will draw the rod 12and gripping'member 13' from the 'dotted line position shown in Fig. 1 to the full line position shown therein.

The said pivoted levers 11 carrying said gripping member 13 being eccentrically mounted with respect to the platen will cause the extensions 9 of said frame members and 7 to rise somewhat as thesaidv gripp ng member 13 grips the surface ofthe platen 2, or rather as the said gripping member 13 grips the papercarried by said platen the weight of the frames 6 and 7 and their associated parts serve tohold the-gripping member 13 in close contact with the said paper.

In addition to the above, the extreme ends 63-of the said gripping member 13 are, as

best shown in Fig. 2 extended beyond the edges of the paper 58 and they likewise causethe resilient material of the gripping member 13 to contact with the platen 2, so

' that a firm gripping is-had on the platen and paper which causes the platen to be turned as the flexible members 14 and 15 are pulled in the manner just disclosed.

- As the solenoid. core 25 however is sucked into the solenoid its pivot 24 catches on the forked-end 48 of the lever 46 turns said lever on its pivot 4:5' 2H1d thus moves the insulated portion 47 of said lever from itsposition in contact with said spring members 42 and 41, to a position out of contact therethe springs '68 and 69 which are respectively connected with the frames 6 and 7 and the gripping memher l3 now cause said gripping member to move from its full line position toward its dotted 1 line position shown in Fig.-1. But owing to the rapidity with which succeeding breaks and makes of said circuitis had-said gripper does not reciprocate over an arc. sufiicient to permit the letter thatis to'be erasedto return to its normal position under the ribbon 4, but said reciprocations cause it to oscillate under said eraser 56 'as will presentlylappear,

The movement-of said gripping member 13 from its said full line position toward its dotted line position further causes the connections 14 and 15 and bell cranks 16 and 17 to pull the solenoid coresout of the sole noid and into the full line position shown in Fig. 2 and the corresponding movement of the solenoid 25 causes the lever 46 to he swung on its pivot 45 back into the full line position shown in saidFig. 2whereupon the circuit is-again'madejat' the contacts 41 and 42, and the operation is repeated. In other words, so long as no pressure is-cxcrted hy' the operator on the eraser 56 the platen 2 with the paper will first be so revolved as to bring the character in position to be erased and out from under the ribbon 4.

whereupon said character will be oscillatedunder said-eraser. "When the circuit is finally broken the platen will be returned to its normal position. It therefore follows that when the operator holds the eraser 511 over and in contact with the character to be erased, the said reciprocations of said paper and platen will cause the eraser 56 to obliterate the said character. v

Of course, in addition to the above. it the operator so desires he may rotate the said eraser on its pivot and thus aid the motion of the parts int-erasing the character. to fore the platen 2 can be fllllSOSClllflittl. how ever, it must be released from its detem 5.3. Such release is automatically accomplished when the lever 30 is thrown from its dotted line position to its full line position shown in Fig. 1. That is to say the pin 49 reaches the end of the slot 50 in the member 31 and the said member 51 pulls the detent 53 from ,the dotted line position shown in said Fig.

1 to its full line position. actor has been thus erased by tlnpwing the lever 30 from its full line position to its dotted line position shown in Fig. 1. the extension 34 of the bracket 33 contacts with the frame member 6 on the left hand side of its pivot 5, and thus restores the parts to their dotted line positions all as will be clear from said Fig. '1. 4

' In the somewhat modified form of the invention illustrated in Fig. 3. the parts which have been just described and which are retained in. said figure have received the After the charextension 80 and which is'pivoted on the rod or bar 8 as shown. This said rod or bar 8 is provided with a roller like member 81 which serves as a clamp. The frame member 6 is provided as at 82 with the member 83 which carries the clamping member 8& adapted to contact with the paper at about 120 or 145 from the contact of the clamp 81, and to said member83 is pivoted-as at 85 the reciproeating member86 provided with the slot 87 in which works the 'pin 88 carried by the lever 30. -The operation of this said modified construction shown in Fig. 3 is as fol-' lows :WVhen the lever 30 is thrown from its full .line position, in said Fig. 3', to its dotted line position corresponding to that shown inFig. 1, the extension 31 of said lever 30-strikes the extreme end 90 of the frame member 6 and tips said frame member together with all of' its associated parts into a dotted line position, not shown, but

which corresponds with the dotted line positions shown in Fig. 1.

As said frame member 6 rises a lug 91 carried thereby contacts with the member 7 O and likewise causes said last named member and its associated parts to rise. The spring 60 passes to the left hand s1de of the pivot '5 and holds the parts in their inoperative position all as was explained inconnection with Fig. 1. On the other hand,

wvhen the lever 30 is thrown to its full line position, shown in Fig. 3, then the circuits are closed, the solenoid 23 is excited, the

' bell cranks'16 and 17 'cause a reciprocation of the ripping member-13, and a consequent oscillation of the platen 2, all as was explained in connection with Fig. 2. In this particular form of the invention, should a multiplicity of copiesbe associated with the platenmember, the clamping members 81 and 82 serve to hold all of. the sheets of paper in place so that thesaid papers are firmly oscillated with the-sald platen 2. The clamping member 81 is held to its position by gravity as well asby the spring and the clamping member 84: is carried into its operative position by the movement of said lever 30 all as will be clear from the drawings.

In this modified form of construction the thumb extension enables the operator to .the form shown in ing, I provide a switch 100 adapted to short switch 32 as illustrated in Fig. 2, leaving the ing movement, substantially as described.

ables him to throw the lever 30 in one position or the other as he desires, andtherei fore, it is more conv nient to operate than is ig.'1. The extension 9 6 may reston any'por 97 rof the frame work,-and as it is cor outed tothe eraser 1 member 56 it enables the operator to move said'eraser member to any erasingpositiora desired as well as .to exert pressurejthereon; i? to facilltate ,the erasing operation. I

.. as" .To prevent the platen from returning to its normal position for typewriting wheneverthe eraser frame is raised to move a carbon sheet in or out of position for eras-g 80 circuit the contacts 11 and 42'. This said switch 100 is joined by the wire 101 to the wire 43 andby the w'i refll02 to .the wire 37 and thus cuts out the said contacts and solenoid energized. f

It will thus be seen that when the said switch is closed the eraser frame 6,7 may be raised or lowered at will, without disturbing the erasing position of the platen. It is obvious that thosejskilled in the art may vary the detailsof. the construction without departing from the spirit of the invention, and therefore, I dov not wish to be limited to the above disclosure except as' 95 may be required by the claims. What I claimis:, i 1. In an. erasing means for typewriters'the combination of a platen; a gripping 'mem-fl ber adapted to contact with the paper on 00 said platen; means for reciprocating said gripping member and "oscillating. said platen and paper; and an eraser adapted to contact-with said paper during its'oscillat- 2. In an erasing means for typewriters the combination of a platen; a gripper dis-' posed parallel to and extending beyond the edgesof the paper normally carried by said platen; 'means for automatically oscillating said platen and paper; and an eraser adapted to be held in contact with said paper during its oscillating movements, substantially as described. i j

'3. In an erasing means for typewriters the combination of a platen; a gripper disposed parallel to the paper normallycarried by said platen; means comprising an electromagnetically operated member for automatically oscillating said platen and paper; and' an eraseradapted to be held. in contact with saidpaper during its oscillating movements, substantially as described.

4'. In an erasing means for typewriters the combination of a platen; a gripper disposed-parallel to the paper normally carried by said platen; means comprising a solenoid and a lcircuit closing means governed by said solenoid for automatically oscillating said platen and paper; and an eraser adapted to be held in'contact with saidpaper durin its oscillating movements, substantially as described.

' In an erasing means for typewriters the combination of a platen; a gripper disposed parallel to and extending beyond the edges of the paper normally carried by said platen; a pivoted frame member supporting said gripper; means for automatically oscillat-ing said platen and paper carriedby said frame member; and an eraser associated v p with said frame member adapted to be held in contact with said paper during its oscillatmg movements, substantially as described, 6. In-an erasing means for typewriters the combination of a platen; a pivotedframe; a gripper carried'by said frame adapted to contact with the paper carried by sa1d platen; an eraser carried by said frame adapted to contact with said paper; a. magneto-motive means and connections for contact with the paper carried by said platen;

an eraser carried by said frame adapted to contact with said paper; a magneto-motive means and connections comprising a circuit, contacts for making and breaking said-circuit, and a solenoid in said circuit for reciprocating said gripper and oscillating said platen and paper; and means for holding said framein an inoperative position with said gripper out of contact with said paper, 'substantlally as described.

8. In an erasing means for typewr ters the combination of a platen; a pivoted frame; a

gripper carried by said frame adapted to contact with the paper carried by said platen; an eraser carried by said frame adapted to contact with said paper; a magneto-motive means and connections for'reciprocating said gripper and oscillating said platen and paper; a detent for holding said platen; means connected with said frame for automatically moving said detent and releasing said platen; and means for holding said frame in ,an inoperative position with said gripper out of contact with said paper, substantially as described.

9. In an erasing means for typewriters the combination of a platen; a pivoted frame; a gripper adapted to contact with the paper carried by said platen; means for holding said paper firmly on said platen; magnetomotive means for automatically reciprocating said gripper and oscillating said platen and paper; an eraser carried by said frame adapted to contactwith said paper while being oscillated; and means for rendering said magnet o-n'iotive means inactiveat will, substantially as described.

10. In an-erasing means for typewriters the ;combination of a platen; a gripper adapted to contact with the paper *arried by said platen; a magneto-motive means comprising make and break contacts for causing said gripper to continuously oscillate said platen and paper; and means for short circuiting said contacts and leaving said magneto-motive means energized for holding said platen and paper at the end of one of the oscillating movements. substantially as described.

In testimony whereof I aflix my signature, in presence of two witnesses.

. EL'STIS HENRY THOMPSON. \Yitnesses G ORGE SIIINNA 1105' It. L. T nonrsox. 

